LAWRENCE, Kan. — In a year devoid of a clear national championship favorite, the most significant X-factor in the upcoming NCAA tournament is expected to be the health of a Cameroon native who turns 20 the day the bracket is unveiled Sunday.

When Joel Embiid, the 7-foot Kansas freshman, exited Gallagher-Iba Arena the night of March 1 into a worsening ice storm and with a pronounced limp, needing help just to descend a few steps, the image served as an ominous sign for one of the favorites to win the national championship.

The stress fracture in Embiid's lower back, which was confirmed when he visited a Los Angeles-based spinal specialist this week, will keep him out of this week's Big 12 tournament and likely the first weekend of the NCAAs. If No. 10 Kansas is still alive in the NCAA tournament when Embiid returns, the extent of his health stands to shape the entire event.

Ron Wellman, the chair of the NCAA tournament selection committee, reiterated in a teleconference Wednesday that the committee relies on information from schools pertaining to injuries that could affect tournament seeding.

"We don't have a CIA operation here where we can go in the backdoor and find out information that they are not giving us," Wellman said. "So we do rely upon the school's truthfulness with us and we believe they do tell us the truth."

Regardless of where the Jayhawks will be seeded – they were likely a No. 2 seed with a healthy Embiid and probably won't fall below a No. 3 because of overall strength of schedule – they are fully capable of beating anyone in the nation with Embiid on the court. Kansas coach Bill Self says he has never coached a player with as much upside as Embiid and fellow freshman Andrew Wiggins, two players who helped lead the Jayhawks to at least a share of their 10th consecutive Big 12 regular season title.

Some national contenders possess excellent guard play. Others have tenacious defenders or a roster laden with seniors. A healthy Embiid gives Kansas something else: an agile, shot-blocking 7-footer with a terrific basketball IQ and soft shooting touch, whose skill set only improved with each passing week.

"No one else has one of those," ESPN analyst Jimmy Dykes said.

When Embiid first stepped on campus last summer, Self told him that he would be the top pick in the NBA draft whenever he chose to turn pro. Texas coach Rick Barnes, who was among the finalists to land Embiid, said during the regular season that he is convinced Embiid will be the top pick in this June's draft.

"There is no doubt in my mind," Barnes said.

Kansas has played well this season at times without major contributions from Embiid. The Jayhawks beat Duke, 84-83, on Nov. 12. with Embiid playing 20 minutes and scoring two points.​

And Embiid's absence creates more of an opportunity for 6-foot-9 Memphis transfer Tarik Black, who has averaged 12.2 minutes but has been prone to foul trouble.

After the team's pre-Big 12 tournament shootaround Wednesday in Kansas City, Jayhawks coach Bill Self said of Embiid, "We'll play him whenever the doctors and Joel's body and all that stuff is ready for him to play. And I'm still very confident, as others are, that that is going to happen. To be real candid, we may have to advance (in the NCAAs) for it to happen."

Missing games at this stage of the season would be difficult for any freshman. But it is especially unfortunate for Embiid, who also sat the final two regular season games, because he only first picked up a basketball at 16 years old and was learning at such an accelerated rate. Each game has been critical to his continued development.

CBS analyst Clark Kellogg said it has been "unbelievable how he has gotten better with each game. It almost seems like he has gotten better within games that I have watched."

At times Embiid has marveled at his own development. He arrived in college with an engaging personality, bright smile and curiosity about American culture. He quickly became the most intriguing and promising amateur basketball player in the world, and now his back is at the center of the college hoops spotlight.

The question of his health will hover over the NCAA tournament much like Embiid hovers over diminutive guards looking to attack the rim.

"When I came here, I didn't even think I would get any attention," Embiid said. "I am still a project, but didn't know I would be this advanced with the game at this time. I knew I would keep improving. I didn't know it would be this fast."

***

So many of the top pro prospects – the truly elite players – are stamped as such when they are in the ninth or 10th grade. Because of his journey from Cameroon, Embiid picked up the game late.

But coaches remember the moment they first saw a precocious center with virtually unlimited potential.

SMU coach Larry Brown still remembers the day. He was sitting watching a Florida-based AAU team play, and Embiid hardly ever touched the basketball.

It did not matter.

"I think he touched the ball four times, and I fell in love with him," Brown said. "I just think he is so special. And he went to the right place."

Rob Lanier, the Texas associate head coach, recalls standing in a gym where Embiid was playing and looking to his left and right to see how many other coaches were already onto what he was seeing. It didn't take long before Embiid's potential attracted more suitors.

Everyone who watched Embiid play in his high school days has a story.

"He made a move – I am not kidding you – he made a Kevin Durant-type move where he drove and stepped back, fall-away, and made the shot," Barnes said. "I told Rob, 'He is going to be a great one.' There's something about him. I'm telling you, he has that quiet confidence that you knew."

Kansas assistant Norm Roberts pushed Self to watch Embiid even though, when Embiid had transferred to The Rock School in Gainesville, Fla., for his senior high school season, many individuals on the summer basketball circuit thought Embiid was a lock to attend Florida.

When Self first saw him, he told Roberts, "Wow, he's bigger than I thought you said he was."

"Yeah, he's 7-foot," Roberts said.

"Yeah, he's all of 7-foot," Self said.

On one occasion when they watched Embiid, as the action flowed back and forth in front of the two Kansas coaches, Roberts told Self that Embiid would have to learn to block shots and that Embiid doesn't block shots like he is supposed to.

"Yeah, uh huh," Self said, staring at the 7-footer on the court.

So, Roberts asked, what do you really think?

Self turned to his assistant.

"I don't care what player in America we are trying to get," Self said. "No one is more important than Joel Embiid. That guy is going to be great. He has a chance in two years to be the No. 1 pick in the draft. That guy is terrific, unbelievable. I don't want you to recruit anybody harder than you recruit Joel Embiid. We've got to get him."

Self saw a big man who could slide. He could trap. He didn't yet have post moves, but he had touch on the ball. He was doing things that 7-footers could not do at that age. And he was doing things virtually no one could do after picking up a basketball for the first time just a couple years earlier.

"I knew," Self said. "Right then, I knew. This dude is different. I said, 'Norm, he is going to be better than anyone we have had play the post for us.' "

The day Embiid was supposed to decide on a college, the Kansas staff did not have a feel which way it would go. Then Roberts got a call from Gainesville, Fla., at 8:30 a.m. On the other end was Billy Donovan.

" 'Hey, Norm, I just wanted to let you know, congratulations on Joel. He is going to Kansas. I talked to Joel this morning,' " Roberts recalled Donovan saying. "That is how we knew we would get him. Billy is such a classy guy."

***

When Embiid arrived at Kansas, if there was one thing he was already schooled on, it was Hakeem Olajuwon's patented "Dream Shake".

At 16, Embiid began watching videos of Olajuwon and all of his moves. In fact, Embiid watched a lot of the NBA in Cameroon, so when he arrived in America he was doing one-legged Dirk Nowitzki jump shots.

"That was my favorite move," Embiid said, laughing. "I am 7-feet and my coach in high school did not want any fadeaways."

In early practices at Kansas, he routinely tried to make 15 different moves on one play. Coaches told him just to catch the ball and go into his jump hook, or catch it, spin and go with his left hand.

"There's not the Dream Shake all the time," Roberts said. "Hakeem did not use the dream shake all the time. The thing is, Joel can really do those moves. Sometimes in practice, he will have a four- or five-minute span when he will use it. Coach says, 'Go ahead, if you've got it, go ahead and do it."

Former Kansas all-American Danny Manning said Embiid already demonstrates "some" of the footwork that reminds him of Olajuwon. "He does something every game that really catches your attention," Manning said.

By the start of the season, the whispers about Embiid's rapid development grew louder. ESPN analyst Fran Fraschilla said at Big 12 media day that Kansas may have the No. 1 pick in the 2014 draft – but his name might not be Wiggins.

By the middle of the season the game slowed down for Embiid, and he began playing with more poise in the post.

Then teams began trapping him. He became frustrated and didn't understand how to combat the defensive move. He told his coaches that he hated traps. Coaches explained that it was a huge compliment and showed him how to react to it.

Two days later, he said he didn't mind it anymore. He knew how to score quickly or get the ball out to teammates.

Another nuance Embiid learned was to avoid swiping down to block shots. Coaches gave him a video of former Kansas shot-blocking extraordinaire Jeff Withey, who made a habit of blocking shots and keeping them in play.

Self said Embiid has a competitive streak, and the coach has pressed the right buttons from time to time to light a fire within Embiid. For example, before the Kansas State game, Embiid said, he and Wiggins did not have a good practice.

Embiid remembers Self telling them that they weren't good enough to play in the rivalry game because they were too soft. It lit the fuse within Embiid.

"You just want to get better, and when he tells you that you want to start being dominant to the point where no one can stop you," Embiid said.

***

One of Embiid's favorite television shows is Vampire Diaries. He loves math and is interested in business, but his major may as well be video games.

During an interview with USA TODAY Sports this season, he understandably did not know how many teams were in the NCAA tournament, but he had watched it before, specifically the Kansas-Michigan game from last season.

He laughed at his diet, which he admitted could use a makeover. He loved to eat a ton of brownies – and only brownies – for a meal.

Self said Embiid, in some ways, reminds him of the Tom Hanks character in the movie "Big." He has an innocent enthusiasm to learn about everything on and off the court in America, and he's doing it under a bright spotlight.

"There are so many things that this kid has not experienced at all, and he is just a sponge trying to soak it all up," Self said. "He is a kid in a candy store right now. Just soaking it all up, every aspect of life is so new to him right now. He knows that. I think it is very refreshing."

Embiid has studied former college big men who entered the NBA draft after one season. Self said he has a strong support system around him, including a family that preaches academics and maturity. His mentor Luc Richard Mbah a Moute, a former UCLA player, has provided guidance and advice throughout, Embiid said.

Embiid is the most intriguing and promising player in the nation. The final chapter of his freshman season has yet to be written. And it is bound to be a memorable one because it not only affects Kansas but also the entire three-week NCAA tournament.

"Obviously the big fella makes a big difference in having a chance to win it all," TCU coach Trent Johnson said. "They need to have him in the stretch."